The present invention relates to a jet injector and in some embodiments a needle-assisted jet injector that uses a low jet injection pressure and has a lock ring that provides breakaway force resistance.
Certain jet injection devices have needle guards that must be retracted prior to insertion of the needle and triggering of the jet injection. A certain amount of force is normally required to trigger the jet injection. To assure sufficient needle guard travel for needle insertion and triggering, it is at times desirable to require a breakaway force prior to significant needle guard retraction to assure that insertion of the needle and triggering of triggering force is overcome. The present invention addresses this problem.